Substituted dihydroxy-diphenyls



Patented 28, 1941 a v UNITED, STATES PATENTTIOFFICE SUBSTITUTED DIHYDROXY-DIPHENYLS Edgar 0. Britton and John E. Livak, Midland, Mich., assignors to The Dow Chemical Company, Midland, Mich., acorporation of Michigan No Drawing. Application June 23, 1939,

Serial No. 280,846

2 Claims. (Cl. 260-620).

This invention" relates to certain new derivaetc., in the known manner to form an o-hexyltives of 4.4-dihydroxy-diphenyl and inparticuphenyl ether, e. g. o-hexyl-anisole, o-hexyllar concerns substituted dihydroxy-diphenyls phenetole, etc., which compound is then reacted having the general formula with iodine in the presence of mercuric oxide R R 5 or other strong oxidizing agent to form the corresponding pi-iodo-o-hexyl-phenyl ether. Two

molecules ofthis latter compound are then condensed, employing copper powder or other suit- Wherein R represents an alkyl group containing able condensing agent, to form a di-ether of at least 4 carbon atoms, a cycloalkyl group, or 3.3 di hexyl 4.4'- dihydroxy diphenyl from an aralkyl group. Examples of such compounds which product, the desired 3.3-di-hexyl-4.4- are 3.3 di-n-butyl 4.4 dihydroxy diphenyl, dihydroxy-diphenyl may be obtained by treat- 3.3- di-isobutyl-4.4-dihydroxy-diphenyl, 3.3 ment with hydrogen iodide. The reactions inditertiaryamyl-4.4-dihydroxy-diphenyl, 3.3-d'1- volved insuch mode of procedure may be repn-octyl-4.4-dihydroxy-diphenyl, 3.3-di-benzylresented as follows:

CaHiz Ce u oHn CaHra 4.4'-d ihydroxy-diphenyl, 3.3-di-cyclohexyl-4.4'- wherein R represents a lower alkyl group. All dihydroxy-diphenyl, etc. v of these reactions are of a well-known type and The substituted dihydroxy-diphenyls having a the most suitable conditions for efiecting them the above general formula are usually obtained will be apparent to those skilled in the art. in the form of white crystalline solids which are The alkyl-substituted dihydroxy-diphenyls substantially insoluble in water but are soluble may also be prepared by the hydrogenation of in common organic solvents, e. g. acetone, pethe corresponding alkenyl-substituted dihytroleum ether, carbon tetrachloride, benzene, droxy-diphenyls, certain of which compounds etc. They are useful as intermediates in the are described and claimed in our co-pending appreparation of dyes and dye intermediates, plas- 40 plication, Serial No. 280,845, filed June 23, 1939, ticizers, wetting agents, pharmaceuticals, toxinow matured into Patent No. 2,229,010, issued cants, etc. Jan. 14, 1941. Thus, 3.3-di-isobutyl-4.4-di- The alkyland cycloalkyl-substituted dihyhydroxy-diphenyl may be prepared by hydrodroxy-diphenyls of the present class may be genating 3.3-di-(2-methylallyl)-4.4-dihydroxyprepared by forming the para-iodo derivative of diphenyl, 3.3-d1 n hexyl 4.4'- dihydroxy dithe corresponding ortho-alkyl or cycloalkyl phenyl by hydrogenating 3.3'-di(3-propylallyl)- phenol and thereafter condensingtwo molecules 4.4'-dihydroxy-diphenyl, etc. The hydrogenaof such iodo derivative to form the desired dition reaction is preferably carried out by the hydroxy-diphenyl compound. Since the free hydirect addition of gaseous hydrogen under presdroxyl group of the phenol is reactive under the sure to a solution of the alkenyl-dihydroxy-diconditions employed for these'reactio-ns, it is phenyl'compound in an inert solvent in the necessary to protect the hydroxyl group, for expresence of a hydrogenation catalyst, such as ample, by etherification, during the iodination nickel, platinum oxide, etc. The reaction takes and condensation reactions and thereafter replace quite readily at ordinary temperatures,

generate the free phenol. For example, in pree. g'.' 20-30 C.,'but, if desired, higher temperaparing 3.3'-di-hexyl-4.4'-dihydroxydiphenyl, tures may be employed. Upon completion of o-hexyl-phenol is first reacted with an alkylatthe reaction, the catalyst is filtered off and the ing agent, e. g. dimethyl sulphate, ethyl chloride, 1 hydrogenated product recovered directly from the reaction mixture and purified by crystallization from a suitable solvent.

The aralkyl-dihydroxy-diphenyls of the present class may be prepared by the condensation of a p-iodo-o-aralkyl-phenyl ether, as hereinbefore described,although they are more conven-- iently prepared by the direct aralkylation of 4.4- dihydroxy-diphenyl. In carrying out such reaction, the 4.4'-dihydroxy-diphenyl is first reacted with an alkali to form an alkali-metal salt thereof and the latter compound is heated with an aralkyl halide, e. g. benzyl bromide, alphachloroethyl benzene, etc., at reflux temperature until the reaction is complete. In the absence of excess alkali, the desired product is formed Example 1 256 grams of iodine was added in 30 gram portions over a period of 20 minutes to a mixture of 190 grams of o-cyclohexyl-anisole (prepared by the methylation of o-cyclohexyl-phenol) 108 grams of mercuric oxide, and 550 grams of thyl alcohol maintained at a temperature of about 25-55 C. The mixture was then heated at reflux temperature for 4 hours after which time it was cooled and filtered, and the alcohol was removed by distillation. The distillation residue was washed with a dilute aqueous sodium bisulfite solution to destroy unreacted iodine, and the washed product was extracted with carbon tetrachloride. The carbon tetrachloride extract was then fractionally distilled whereby there was obtained p-iodo-o-cyclohexyl-anisole, an oily liquid distilling at approximately 165-1'75 C. under millimeters pressure. A mixture of 110 grams of this product and '75 grams of copper powder was heated at a temperature of about 260-300 C. for hour after which time the mixture was cooled and extracted with benzene. The benzene was evaporated from the extract and the crystalline residue was recrystallized from glacial acetic acid whereby 3.3-dicyclohexyl-4A-di-methoxy-diphenyl was obtained in the form of glistening white plates melting at 174.5-1'75.5 C. 28.4 grams of the 3.3 -di-cyclohexyl-4.4 -di-methoxy-diphenyl thus obtained was then dissolved in approximately 100 grams of phenol by warming to 120 C., and 72.7 grams of hydrogen iodide in the form of a 5'7 per cent aqueous solution was added gradually with stirring. The mixture was then heated at reflux temperature (125 C.) for 2 hours after which time it was cooled and poured into 500 cc. of water, whereby the 3.3'-dicyclohexyl-4.4- dihydroxy-diphenyl product was precipitated as a white crystalline solid. After recrystallization from glacial acetic acid, this compound had a melting point of 209-213 C.

Example .2

11.3 grams of 3.3-di-(2-methylallyl)-4.4-dihydroxy-diphenyl (M.P.=979'7.5 0.), prepared by the rearrangement of 4.4-di-(2-methylallyloxy)-diphenyl, was dissolved in 60 grams of ethyl alcohol, and, after the addition of 0.1 gram of platinum oxide, was treated with gaseous hydrogen under pressure in a Burgess-Parr hydrogenation apparatus. The theoretical amount of hydrogen (0.08 mole) was absorbed in about 3 minutes. Upon conclusion of the hydrogenation, the alcohol solution was filtered to remove the platinum oxide catalyst and the filtrate was evaporated to dryness on a steam bath. The residue was recrystallized twice from a benzenepetroleum ether mixture whereby 3.3-di-isobutyl-4.4-dihydroxy-diphenyl was obtained in the form of a white crystalline solid melting at 136-138 C.

Example 3 A suspension of 53.2 grams of the di-sodium salt of 4.4'-dihydroxy-diphenyl in 345 grams of toluene was heated to reflux temperature to drive off water of crystallization after which time 50.6 grams of benzyl chloride was added gradually with stirring at a temperature of about 25 C. The mixture was then heated at reflux temperature (112 C.) for 8 hours, cooled, washed with petroleum ether and water, and filtered. The precipitate, consisting of crude 3.3'-dibenzyll.4- dihydroxy-diphenyl, was digested with dilute aqueous sodium hydroxide, filtered, and the alkaline filtrate was acidified with dilute aqueous hydrochloric acid, whereby the 3.3-dibenzyl-4.4- dihydroxy-diphenyl product was precipitated as a white crystalline solid. After two recrystallizations from benzene, the compound had a melting point of approximately 151-158 C.

Other substituted dihydroxy-diphenyl compounds of the present class which may be prepared as herein described include 3.3-di-tertiarybutyl-4A -dihydroxy-diphenyl, 3.3 -di-n-heptyl-4.4'-dihydroxy-diphenyl, 3.3-di-isoamyl-4.4'- dihydroxy-diphenyl, 3.3-ditertiaryaryootyl-4.4'- dihydroxy-diphenyl, 3.3"-di-beta-phenylethyl- 4.4'dihydroxy-dipheny'l, 3.3-di-cyclopentyl-4.4- dihydroxy-diphenyl, 3.3-di-gamma-phenylpropyl-4.4'-dihydroxy-diphenyl, 3.3-dilauryl-4.4'- dihydroxy-diphenyl, etc.

Other modes of applying the principle of our invention may be employed instead of those explained, change being made as regards the method herein disclosed, or the materials employed, provided the products stated by any of the following claims or the equivalent of such stated products be obtained.

We therefore particularly point out and distinctly claim as our invention:

1. A substituted dihydroxy-diphenyl compound having the general formula 2 z I I wherein Z represents an aralkyl group.

2. 3.3 dibenzyl 4.4 dihydroxy diphenyl, a white crystalline solid having a melting point of approximately 151-158 C. and the formula EDGAR C. BRITTO'N. JOHN E. LIVAK. 

